A project to perform a powertrain Noise Path Analysis (NPA) on a two-wheel rear drive vehicle was performed at Visteon Corporation. Research engineers gained insight into the NPA procedure as applied to a typical medium-duty production pick-up truck. Visteon's interest in this project was two folded. First, to do a full experimental Noise Path analysis (NPA) and then, develop a methodology to integrate the experimental measurements and analytical results into a unified model to predict the responses at passenger interface points within a vehicle.
This presentation will cover the details of the experimental NPA including measurement locations, transducer types and placement, elastomeric mount characterization, and the matrix inversion process required for indirect force estimation. Both the direct mount method and the indirect force methods based on matrix inversions were used for several mount locations to allow the estimated forces from two independent methods to be compared for accuracy and verification. Finally, subsets of forces were estimated from analytical models and compared to the experimentally determined forces.
This process allows Visteon to predict passenger response interface point amplitudes from a combination of their Finite Element Powertrain models and P/F body measurements supplied by the OEM to characterize the transfer paths. This process gives Visteon the ability to enhance their driveline subsystem NVH performance relative to the sensitivities for the receiving body structure.